And now for the good news ...

Lucian Msamati cut his teeth doing political theatre in Zimbabwe. Now he has a lead role in Alexander McCall Smith's rose-tinted vision of Africa. He tells Aida Edemariam about the filming of The No 1 Ladies' Detective Agency

'It was between acting and playing for Liverpool' ... Lucian Msamati. Photograph: Sarah Lee

A deep, wicked laugh rumbles through the room as Lucian Msamati talks about his latest acting job, in the TV adaptation of Alexander McCall Smith's novel The No1 Ladies' Detective Agency. It's not quite in keeping with his role as the dignified garage owner who wins the heart of a "traditionally built" Botswanian private eye, but Msamati can be forgiven a certain exuberance. Not only are McCall Smith's novels hugely popular, but the script has been co-written by the ever-popular Richard Curtis, and there are 12 more episodes to follow. Unless something goes disastrously wrong, Msamati is on his way to becoming part of Britain's cultural landscape.

Msamati, 32, has been acting, or wanting to act, since before he can remember - as his parents, a doctor and a nurse, often tell him. They are Tanzanian, but he was born in the UK and grew up in Zimbabwe. "It was between acting and the possibility of playing on the wing for Liverpool football club," he says, with another big laugh. "You can tell which era lots of Africans grew up in by which football team they support. There was a whole wave of us who supported Liverpool or Manchester United. And now, of course, you have your Arsenals and your Chelseas ..." He sounds unconvinced by these Johnny-come-latelies.

Msamati went to one of the best schools in Harare, where Gilbert and Sullivan was as popular as plays written by the students themselves - often by Msamati, for whom writing seems always to have gone hand in hand with acting. It took a while for his parents to be convinced by his choice of career. "It was expected that I would follow a more traditional route in life ... It took a long and painful time for my parents to accept it."

There were theatres in Harare, but none of them was putting on anything that Msamati and his friends really wanted to watch, so they set up their own company, Over the Edge: a young, multiracial group, whose first production was Macbeth. It's tempting to assume that there were political reasons for staging a play about the battle between might and right, but Msamati insists there was nothing more to it than a love of Shakespeare. "Growing up in countries like these," he says, "it's very hard to explain to people that life [in Zimbabwe] is not a long, ongoing Greek tragedy. We're not sitting over a campfire saying, 'Oh, what shall we do - the masses are starving.' That's not what happens. Life goes on as normal."

The company was writing topical material, though, including sketches about current affairs. "Stuff that made us laugh, and stuff that people of our ages responded to" - so well, in fact, that in Harare and among the newspaper-reading classes generally, they were soon famous.

So their first visit to the Edinburgh Fringe, in 1998, was a bit of a shock. They had read up on the festival beforehand, knew that it could be anarchic, a bit overwhelming - but "you can research up the wazoo, but never know what it's really going to be like". So they were unprepared for organisers' broken promises, for snide racist comments, for performing - in Msamati's case - barefoot on a basement floor covered in green slime: "It was an unmitigated disaster."

They were eventually reviewed, and well, by the Scotsman, but it was "too little, too late". Back in Zimbabwe, however, "after we'd recovered and done the postmortems, we were like, 'You know what, let's go for it again - but this time let's do it under our own steam, because we know what it is we need to do.'" And so they returned, every year, until 2001, getting better and better audiences, better slots, more invitations to tour - often with plays Msamati had written, such as Eternal Peace Asylum, which tackled, directly, the worsening situation in Zimbabwe.

"I had always maintained, and always knew," says Msamati, "that in order to make it in this profession I would have to leave Zimbabwe eventually." So in 2001 he and three friends stayed on in Edinburgh, renting a flat together. Msamati worked as a cleaner for a while, to make ends meet. In 2002, he made the move properly. "Things in Zimbabwe were not going great. We were getting increasingly angry, and a lot of our anger was getting into our material. It was getting a lot edgier - and that was when I started thinking about making a move. And one thing led to another ..." Since then he's been in Antony Sher's ID, about the assassination of Hendrik Verwoerd, the architect of apartheid, Steven Knight's The President of an Empty Room, at the National Theatre, and Pericles for the Royal Shakespeare Company. One critic said that his last stage role, in Bertolt Brecht's The Resistible Rise of Arturo Ui at the Lyric Hammersmith, earned him a place "in the higher rankings of London acting talent".

Did Msamati find Harare dangerous? "Yeah, we all did. We didn't know from one day to the next what was going to happen. We didn't know if we were going to fall into a riot or demonstration, you didn't know what was going to be in the shops, you didn't know who was going to get beaten up or -" Did that happen to people he knew? "Yeah, oh, yeah. We all took part in a big demonstration - the first big one that went around the world. And friends of mine were attacked, physically assaulted by the government's supporters. But then, the irony was, as we were all running away from the police, jumping into cars, getting out of the city centre, not 10 minutes away, back in the neighbourhood, people are just going about their business. It's a happy Saturday afternoon, they're chilling outside Nando's, having coffees at the bakery - that was also a big shock."

What does he think of the reporting on Zimbabwe in the British media? "Well," he begins, heavily, "the constant filter is white and black, isn't it? It became international news when white people were in trouble. Let's be honest - white faces in peril sell newspapers. It makes the world take notice." Similar things happen all over Africa, and never get reported in the same shocked way? "Unfortunately, yes. And so it's sad, but I'm not going to sit crestfallen and be all, 'Oh, howl, what a shame.' I'm hoping that - certainly in the work that I do, and maybe the Detective Agency - we can start to challenge these stereotypes and these ideas."

That, one imagines, was also the hope of Anthony Minghella, whose last job before his untimely death this week was directing Msamati in The No 1 Ladies' Detective Agency. Msamati has fond memories of filming in Botswana. "Anthony was like a big kid, a big flirtatious kid. He was always laughing, joking, singing. It really added to the warm, creative atmosphere that we worked in."

What does Msamati make of the criticism often levied against McCall Smith: that he paints too rosy a picture of Africa with his pastoral idylls unwracked by Aids, his refusal to countenance war and famine. "Well, I guess the counterpoint to that is if it were in a quaint Scottish village up in the Highlands, it wouldn't be a problem - so why should it be a problem that it's a somewhat idealised vision of Africa? Why not? It's part of building a canon, isn't it? You don't just build one side of ... of the colossus - you have to build all sides of it. And fundamentally, the fact that you've got an overweight, independent African woman doing her own thing, setting up a business, actually dealing with people who are human beings going about their daily lives, who are not dying of A B C D E F G, or under the cosh of some crazed dictator - that's got to be positive.

"I've always been passionate about the way Africans are perceived, and the way I am perceived" - the occasional imputation, for example, that he's only done well here because of the colour of his skin - "and that has always been, fundamentally, something I've battled with throughout my career. I've made it a point that I must make sure that I am the best at this. The slightest mistake, the slightest hair out of place, and someone's going to say, 'Oh well, you see? Bless. They're not very good, are they?'".